Entire to Luxborough, Summersetshire from London in 1771, with a manuscript Harwood London Receiver ?

The entire below was sent from London to Luxborough near Dunster in November 1771.  It has a triangular London Penny Post Paid handstamp, a red manuscript "Harwood", a London bishop mark for 17th November and manuscript "4" and a smaller "5" for postage.

"Harwood" may be the name of the London receiver, though I cannot find a "Harwood" in Hugh Feldman's "Letter Receivers of London".  The sender has paid 1d for the London local post (hence the triangular "Penny Post Paid" mark), and the General Post to Dunster would have been 4d for over 80 miles.  The smaller "5" could be the total charge including local delivery to Luxborough.